Engineering calculators.
Thirty-five dedicated calculator pages with formulas, worked examples, mistakes to avoid and related resources.
Bolt Torque Calculator
Estimate bolt tightening torque from preload, nominal diameter and nut factor.
Open calculator →FastenersTap Drill Calculator
Estimate the tapping drill diameter for common metric threads.
Open calculator →FastenersClearance Hole Calculator
Look up close, normal and loose metric bolt clearance-hole sizes.
Open calculator →FastenersThread Pitch Calculator
Convert threads per inch to metric pitch, or metric pitch to TPI.
Open calculator →MaterialsSteel Plate Weight Calculator
Calculate steel plate mass from length, width, thickness and density.
Open calculator →MaterialsRound Bar Weight Calculator
Calculate the mass of solid round bar from diameter, length and density.
Open calculator →MaterialsPipe Weight Calculator
Estimate hollow circular pipe or tube mass from outside diameter and wall thickness.
Open calculator →MachiningSurface Speed Calculator
Calculate cutting surface speed from tool or workpiece diameter and RPM.
Open calculator →MachiningSpindle RPM Calculator
Calculate spindle RPM from cutting speed and tool or workpiece diameter.
Open calculator →MachiningFeed Rate Calculator
Calculate milling feed rate from RPM, flute count and chip load.
Open calculator →ElectricalVoltage Drop Calculator
Estimate DC voltage drop for a two-conductor cable run.
Open calculator →ElectricalBattery Runtime Calculator
Estimate battery runtime from voltage, amp-hours, usable capacity and average load.
Open calculator →MechanicalHydraulic Cylinder Force Calculator
Calculate ideal hydraulic cylinder extension force from pressure and bore diameter.
Open calculator →MechanicalBelt Length Calculator
Estimate open-belt length for two pulleys from diameters and centre distance.
Open calculator →MechanicalGear Ratio Calculator
Calculate gear ratio and driven-shaft speed from tooth counts.
Open calculator →ConstructionConcrete Volume Calculator
Calculate concrete volume for a rectangular slab, footing or pour with waste allowance.
Open calculator →StructuresBeam Deflection Calculator
Estimate centre deflection of a simply supported beam under a central point load.
Open calculator →WeldingWelding Heat Input Calculator
Estimate welding heat input from voltage, current, travel speed and process efficiency.
Open calculator →FluidsPump Power Calculator
Estimate hydraulic pump input power from flow, pressure rise and efficiency.
Open calculator →HVACAir Changes Per Hour Calculator
Calculate room air changes per hour from airflow and room volume.
Open calculator →ConversionsTorque Converter
Convert N·m, lbf·ft and lbf·in.
Open calculator →ConversionsPressure Converter
Convert bar, psi, kPa and MPa.
Open calculator →Conversionsmm ↔ inches Converter
Convert millimetres and inches.
Open calculator →ConversionskW ↔ hp Converter
Convert kilowatts and mechanical horsepower.
Open calculator →Conversions°C ↔ °F Converter
Convert Celsius and Fahrenheit.
Open calculator →ElectricalOhm’s Law Calculator
Calculate voltage, current, resistance and power from two known electrical values.
Open calculator →MechanicalPulley Speed Calculator
Calculate driven pulley speed from driver speed and pulley diameters.
Open calculator →MechanicalCylinder Volume Calculator
Calculate cylindrical volume from diameter and length, with litres and cubic metres.
Open calculator →ElectricalElectrical Power Calculator
Calculate DC electrical power, current or energy from voltage and current inputs.
Open calculator →ConversionsForce Converter
Convert force between newtons, kilonewtons, kilogram-force and pounds-force.
Open calculator →ElectricalMotor Current Calculator
Estimate single- and three-phase motor current from power, voltage, efficiency and power factor.
Open calculator →FluidsFlow Rate Converter
Convert L/min, L/s, m³/h and US GPM.
Open calculator →ConversionsMass & Weight Converter
Convert kilograms, grams, pounds, ounces and tonnes.
Open calculator →ConversionsArea Converter
Convert common metric and imperial area units.
Open calculator →ConversionsVolume Converter
Convert litres, cubic metres, US gallons and cubic inches.
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